Remote control system



Feb. 16, 1932. M, NELSN 1,845,321

REMOTE CONTROL SYSTEM Filed April 2, 1928 STEP 0746.

nurLnr' Mal-'Im L. Ns Zsnn Patefed Feb. '16.1932

UNITED` STATES PATEN'I?v oFFlcE MARTIN' L. NELSON, OF PARK RIDGE, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,

T ASSOCIATED ELECTRIC ILABOIBA'JEORICES, DIC., OF CHICAGO, ILLINOIS, A CORPORA- TION OF DELAWAEAE l morn commu. sYs'rEm applicati@ mea April 2, 192s. serial No. 266,827.

`the invention, briefly stated, is .the produc` tion of a new and improved remote control system of this type, the im rovements permitting greater flexibility o operation wlthout Il@ increasing the initial cost and maintenanceexpense.

ln commercial installations, it fre uently happens that there are a large num r of switching devices to be controlled, and that' these switching devices are widely distributed, that is, there are but one or two of the devices at any one point. For example, along a railroad line there may be a plurality of` semaphores or lamp operated track side signals, distributed throughout the length of the railroad. At any one point, there vwill be only one or two of these signals, and it is to' the selection and control of the signals in a system of this kind that this invention is directed. Similarly in a power distribution system, a transmission line may radiate, out from a power station, and have a plurality of feeder circuit breakers connected to it at various distributing points, there being but s@ one breaker at each of these points. A dispatcher located at a central point in either of the above systems, may desire to select and opera any one of the devices along the route. ln accordance with established practice in systems of this kind, after the dispatcher has made the selection, he must receive a checkback indication to advise him of the fact that his selection has 'been accurately made. After receiving this check-back further operating is required on the part of the dispatcher to control the selected device.

As kan object of the present invention, I provide a new and improved remote control system of the tandem type, in which the check-back indication is given audibly, that indication serving-not only to indicate the position of the selecting switch, but by means of varied tone signals indicates the actual position of the selected device. AAs a further object of my invention, I provide circuit arrangements which enable the dispatcher to select a device, and to operate it a plurality of times without releasing his selecting switch and reoperating it to reselect the device.

This and other objects not specifically mentioned will be best understood from the reading of the detailed description and claims which follow.

The drawing, shows a suiiicient detail to enable a clear understanding of my invention. `The dispatchers station R comprises a' calling device 30, battery 31, hook switch 32,

telephone receiver D and a condenser. Thel calling device is preferably of the type commonly used in automatic telephone systems.

Leading out from the dispatchers station D is a two-wire trunk, across which trunk arebridged the linerelays of each of the substations. The substation A,'which is shown l in full, comprises the selecting switch H, the

control' relays 9 to 13 inclusive which are adapted. to be selected by the control switch H and operated to control the lamp signals '(9 .and 80. Associated with the control switch is the counting switch CS which is operated responsive to an operation of the switch H to send back over the trunk a code of audible 'impulses indicating the number of the bank contacts upon which the connecting switch H is resting. The connecting switch H is preferably of the type of the well'known connector switch used in automatic telephone systems, a switch which is shown on page 1l 'and described upon the succeeding pages of the book Principles of Automatic Telephgonyi by Harry P. Mahoney. This switch, comprises a shaft carrying a group of wipers, which are moved first in'a vertical direction responsive to one digit received by the switch to select 4a. level in the bank, and then in a horizontal direction to select a Contact in that level. The bank comprises 100 contact sets, arranged in ten rows orlevels with ten contacts in each row. The circuits of the switch H are varied from the standard connector inaccordance with the objects of the present invention.

The counting switch (LSk is a' mechanism similar to the rotary lineswitch of the auto matic telephone system, with the wipers of the switch replaced by the cams which control springs 68 and 69. A switch-of this type, 1s shown in Fig. 45 on page 38 of the above referred to text book.

For the purpose of example, the lamp 80 is assumed to be the green lamp of a lamp signal located along the side of a railroad track, and is lighted at the present moment to indicate a clear track. If the dispatcher at the station D desires to alter this signal, he removes the receive-r R from theswitchhook, operates the calling device in accordance with the digits of the station controlling the lamp 80. Assume for the moment that this is station #62, the dispatcher will dial a 6 followed by a 2. Responsive to the reception of the 6, the connecting switch H will elevate the wipers 55 and 56 six verticalsteps, and responsive to the receipt of the digit 2 will rotate these wipers two steps in a horizontal direction into engagement with thel which the dispatcher hears will be generated by the low pitch buzzer 25, the receiptof that low pitched tone indicating to Vthe dispatcher that the lamp 8O is' burning. Upon hearing this check-back signal, the dispatcher reoperates his calling device 30 to transmit another digit whereupon the relays 9 to 13 are actuated to extinguish the lamp 80 and to light the lamp79. The dispatcher is informedthat'thegreen lamp 80 has been extinguished and the red lamp 79 lightedvby a change in the tone which he receives back from the substation.'A The operationfof relay 9 actuates' springs 58, which cuts off the low pitch buzzer 25 and inserts in its placethe high pitched buzzar 26. The dispatcher then hears that the signal has been set to red or danger. If for any reason the dispatcher desires to reset the signal to clearthat is to re-light the green lamp 80,he merely sends another digit by manipulating his calling device, whereupon the relays 9 to 13 are reoperated to extinguish the red lamp 79 and light the greenlamp 80. The pitch of the tone which the dispatcher hears 1s altered by .the operation o'f' springs 58, so that the new signal comes in in a low pitched tone generated by the buzzer 25.

In the other substations along the trunk, such as substation B, the line relay 27 follows the impulses lgenerated by the calling device, and the connecting switch H isV stepped up and around to its 62nd branch contact position. However, the substation A is the only substation having circuits extendf operation of the connecting switch H', and

the other connecting switches on the trunk' are without effect. 4

Having thus described my invention in general, I will now proceed with a detailed description of its operation.

Calling substation A When the dispatcher removes the receiver R from the switchhook, a circuit is closed 'from the positive pole of battery 31, through switchhook springs 32, right hand trunk conductor, through the winding of the relay l, substation A, resistance 33; to the left hand trunk conductor, thence back through the calling device 30 to the negative pole of the battery 31. In the substation B, ythere is a path across the two trunk conductors in multiplewith the relay 1, that path including the relay 27 and the resistance 27 Similarly in each of the other substations a line relay and a resistance are bridged across the trunk. The battery 31 is of such a potential that it ewill supply a suliicient current to each of the relays 1 and 27, etc., to properly operate these relays. The resistance 33 and 27', etc., are included in the circuit and are adjusted so that the corresponding relay receives the correct amount of current for its proper functioning. n

The energization of the line relay 1 in substation A closes a circuit from ground through springs 41, through the Winding of the slow to release relay 2 to battery. This relay 2, being equipped with a copper slug on the heel end of its core, indicated by the crosshatched section on the drawing, is made slow to release and will remain energized during the transmission of impulses over the trunk circuit. The energ'ization of relay 2 at springs40 closes a control circuit for the relay 5 which is ineffective at the present time.

At springs 43, relay 2 opens a point in the circuit of the release magnet 15, and prepares device 30 to transmit the digit 6, that being 4the first digit of the substation A, line relay 1 falls back six times, as does the line relay 27 of the substation B and the line relays of each of the other substations on the trunk. Responsive to the deenergization of aline relay 1, spring 41 opens the circuit of relay.

when the dispatcher operates his calling a point in the impulsing circuit of the switch the code 6 2 in a high pitch, informing him H spring contact 42 and its make contact,-

spring 45 and its make contact, thence through the winding of relay 3 and the vertical magnet to battery. The remaining four impulses of vthe digit 6 are transmitted over ythis latter circuit without change, at the end of which time the shaft carrying the wipers 55 and 56 is standing opposite the sixth level of the bank.

When the calling device has ,returned to normal after^-the transmission of, the last vertical impulse, line relay 2 comes to rest energized, and the circuit ofthe vertical magnet and the relay 3 is open a suliciently long time to permit the relay to deenergize.

When the dispatcher transmits the digit 2,

the second digit of the called number of the substation A, line relay 1 falls back twice, each time transmitting an im ulse over the circuit including spring 41 an its break con-l tact, spring 43 and its make contact, oi normal spring 42 and its make contact, spring 45 and its break contact, thence over parallel paths, the one including the winding of the slow to release relay 4 to battery, the other the springs 49 and its break contact through the winding of the rotary magnet 16 to. battery. Relay 4 energizes and remains energized during the transmission of the impulses, magnet 16 energizes and deenergizes with each impulse, each energization advancing the' wipers one stepin a rotary direction. The energization of relay 4, closes a circuit from grounded springs 46 and its make contact, springs 48 and its break contact, through the winding of relay 6 to battery, energizing the relay 6. Relay 6 at springs 51, prepares a point in the circuit of relay 5, however, re lay 5 is short circuited at the moment, having ground placed upon its lower terminal by the springs 40 of relay 2, and upon its upper terminal by the springs 46 of the relay 4. i ,c ,Y

Afterthe transmission of the digit 2, the wipers and 56 are resting upon this 62nd bank contact set that is the set sho'wn in the drawing leading to the control relays yof the substation A. Relay 4 deenergizes a brief" interval after the transmission of the last impulse, and at springs 46 removes the v short circuit .fromCthe relay 5, which eneron springs` 40, through relay 5, through `springs 51, through relay 6 to battery. Re-

lay 6 is maintained energized over this circuit. The energization of relay 5, at springs 49, opens a point in the circuit of the rotary magnet, so that the transmission of further impulses to the switch will not move th'e wipers. At springs 48, relay 5 opens the initial energizing circuit of relay 6, without eifect at this time since that relay is maintained energized through springs 51. At springs 47, relay 5 prepares a point in the circuit of wiper 55, thatv circuit being open at the present time at springs 46 and 52.

The check-.back s igmzl The energization of relay 5 closes springs 50, thereby closing a circuit from ground through the wiper 56 and the winding of the relay 24 to battery. Relay 24 energizes over the circuit andv at springs 73 closes a circuit from ground through spring 58 and its :break contact, through the winding of the buzzer 25, through the primary 4winding 82 of the induction coil to battery. Buzzer 25 energizes over this circuit, attracting the armature 76 which short circuits the winding 25 ofthe buzzer. The short circuiting of the Winding 25 causes the armature 76 to be retracted, whereupon the short circuit is removed and the armature 76 reattracted. Thus it will bevseen that the magnet 25 will alternately energize and deenergize, at a speed dependent upon the characteristics of the magnet 25 with respect to the armature 76. This characteristic is one which gives a slow energization of the magnet 25. When the magnet 25 is in series with the winding.

82 ofthe induction coil, a vrelatively small amount of current is iiowing through that inductionA coil. When the armature 76 short circuits the magnet 25,.the `current increases in the winding of the induction coil. This variation of current in the primary winding of the induction coil induces in the secondary winding 81 a voltage which drives current over a., circuit to be subsequently closed, to place a tone back upon the trunk conductor to advise the dispatcher of the position of the switch. Since the buzzer 25 is a low pitched buzzer, the current in the secondary winding \81 will be of low frequency and the tone a low pitched tone.

The energization of relay 24 closes a circuit from ground through springs 72, through spring 67 and its break contact, through the winding of relay 22 and the resistance 23 in parallel to battery. Relay 22 energizes over this circuit, and at springs 71 closes a' circuit from ground on springs 72 through the relay 20 and the resistance 21 in multiple. Relay 20 energizes over this circuit and at springs closes a circuit from ground on springs 72 through the relay 18 and the resistance 19 in multiple.` 'Relay 18 energizes and at springs 67 opens a point in the circuit of relay 22, and closes a circuit tothe motor magnet 17, 'which energizes preparatory to advancing the cams 68 and 69 one step. Relay 22 being slow to release because of the copper slug rupon -the heel end of its core, indicated on the drawingl by the cross sectioned area, is not immediately deenergized but remains energized for a brief interval. When relay 22 eenergizes it opens a circuit of relay 2O which is likewise slow to release.` When relay 2O deenergizes it opens the circuit of relay 18 which deenergizes relatively quickly, and opens the circuit of the magnet 17 which deenergizes and advances the cams one step.

The deenergization of relay 18 likewise re-` closes the circuit of relay 22 which is again operated. Advancement of the cam 69 in contact, springs 68, the condenser, right hand trunk conductor, hookswitch springs 32, the

lreceiver R, the condenser, left hand trlmk contact, through the winding 81 of the induction coil. The tone induced in the winding 81 of the induction coil by the buzzer 25 is thereby made audible to the dispatcher through the receiver R. As the code switch CS advances, springs 68 are closed 6 times, then there is a pause equal to two steps of tho code switch. Aand then the springs 68 are again closed two times. The dispatcher therefore hears the code 6 pause 2, in a low pitched tone, which informs him that he has selected the device 62, and that that device is in. its normal position.

Operating the selected device After the dispatcher has listened to the code indication long -enough to determine whether or not he has selected the desired set of contacts and whether or not the selected device is in the position that he thinks itis,

lhe may alter the position of the selected dehowever, from ground on spring 41, through spring 43 and its make contact, off normal spring 42 and its make contact, springs 45 and its break contact and thence over parallel paths, one through the winding of slow to release relay 4, to battery, and the other through spring 49 and its make Contact, spring 53 and its break contact, through the winding of relay 8 to battery. The energization of relay 4 over this circuit, closes at springs 46 "a point in the circuit of relay 7, however, the relay 7 does not. energize at this time. The energization of relay 8, at springs 54 closes another point in the circuit of relay 7, to short circuit that relay during the time of the impulse that the relay 1 is deenergized. When the relay 1 pulls up at the end of the rst impulse of the digit dialled by the dispatcher, the short circuitris removed from relay 7, and that relay energizes over a circuit traceable from ground to springs 46, relay 7, springs 54, and the Winding of relay 8 to battery. Relay 8 is maintained energized in series with relay 7 over this circuit. `Relay 7 at springs 53 opens the initial energizing circuit of relay 8, to prevent' another impulse from short circuiting relay 7. At springs 52 relay'7 closes a circuit to the wiper 55. The additional impulses of' the digit dialled b the dispatcher merely go through the win ing of relay 4 to battery to maintain that winding energized for a short interval of time. A circuit may now be traced from ground on spring 46, through springs 47, springs 52, the wiper 55, andthe 62nd'bank contact that it is engaging, springs 57 and its break contact, through springs 61, through the winding of relay 10 to battery. Relay 10 energizes over this circuit, and at springs 59 opens a point in the circuit of relay 11. At springs 83, relay 10 locks itself through the ground placed on thebank contact by wiper 55, independently of the springs 57 and 61. At springs 60, relay 10, closes a circuit from ground to the winding of relay 12 to battery, energizing the relay 12 which locks itself through springs 64 and 65 to ground. The energization of relay 12, operates springs 66, to extinguish the green light and to light the red lamp 79 over circuit from ground, through spring 66 and its make contact, through the lamp 79, through the winding ofy relay 9 to battery. Relayv 9 is of low resistance and 'does not materially dim, the lamp 79.- The energization of relay `9, at springs 57 opens a point in the circuit over which relay 10 was energized, without effect at this time since relay 10 is locked through s rings 83 independently of these contacts.

t springs 58, relay 9 opens the circuit, of the low pitched buzzer 25, and closes a circuit of high pitched buzzer 26, the latter buzzer operating to energize the primary winding 82 of the induction coil in the hereinbefore explained manner. The dispatcher, Will therefore be advised of the operation of the lamp signals by a change in the pitch of the code that he receives. He will now receive a high pitched 6 pause 2, to inform him that the red light at substation A is burning.

When the callingdevice 30 returns to its normal position, relay 1 comes to rest enerexplained presently. The result of the dispatcher having dialled the digit after he selectedthe device 62 is to energize the relay 9, and to energize the relay 12, both of which are held up pending further operation on the part of the dispatcher. rIhe red light 79 is lighted and the green light 80 is extinguished.

Assume now that the dispatcher after having set the red lamp at the substation A decides to erase his operation and restore the signals to the position they previously occupied. To do this he again dials a digit operating the relays 7 and 8 in the hereinbefore explained manner, and, operating the relay 4 as before. Acircuit may vnow be traced from ground through spring 4 6, springs 47 and 52, wiper 55v through kspring 57 and its make contact, 59 and its break contact, through the winding of relay 11 to battery. Relay 11 energizes over this circuit, and at springs 62 locks itself to the ground placed on the -contact engaged by wiper l55 independently of the springs 57 and 59. At springs 61, relay 11 opens a point in the circuit of relay 10. At springs 63, relay 11 closes a circuit for the relay 13 which energizes.. At

springs 65, relay 13 opens the locking circuit of relay 12, permitting that relay to deenergize. The deenergization of relay 12 permits spring 66 to break away from its make contact and engage the break contact, thereby extinguishing the lamp 79 and permitting the relay 9 to deenergize, and lighting the lamp 80. The deenergization of relay 9 prepares at springs 57 a point inthe circuit over which the relay 10 was energized, and at springs .58 disconnects the-high'pitched buzzer 26 and connects in its place the low pitch buzzer 25. The dispatcher upon hearing the code 6 2 in a low pitched tone knows that the signals at substation A have been restoredtotheir initial condition.Y

When the calling device returns to normal, and relay l comes to rest energized, the circuit of relay 4 is opened as before, relays 7 and 8 are restored, relay 11-is restored, and relay 13 is restored, thereby restoring the In the switch H, relays 7 equipment to the position occupied in the Release When the dispatcher has completed the operations that he sets about to do, he releases the circuit by replacing the receiver on the hook switch, to break at sprin 32 the circuit of the line re1ay-1 of the station Athe line relay 27 at the station B and the other line relays bridged across theA trunk conductors. Relay 1 falls back, opening the circuit of relay-2, which after an interval falls back and at springs 43 closes the circuit to the release magnet which is traceable from ground to springs 41 and its break contact, springs 43 and its break contact, olf normal spring 44 and its make contact, through the winding of release magnet 15 to battery.. The release magnet energizes and withdraws the retaining pawls from the shaft, not shown, permitv ting the shaft to restore to its normal position, disengaging the wipers ,55 and 56 from lay 2 opens at springs 40 the locking circuit of relays 5 and 6, permitting those relays, to

restore the switch H to its normal position..

the bank contacts. The deenergization of rein connectionwith a. particular class of api' .paratus, I have done' so by way of example only, as there are many modifications which will be apparent to one skilled'in the art which can be made without departing from the scope and spiritl of my invention. I have chosento illustrate the invention in connectionwith the control of. a pair of lamp signals, it being obvious that the lamp signals could be replaced byvoperatingma ets to control either a'semaphore, a circuit reaker, or any other piece of electromagnetic equipment. y y

Having thus describd my invention, what I consider new and desire to have protected by Letters Patent is pended claims.

What is claimed is:

1.' In a signalling system,a device having a plurality of positions, a tone generator for each positionof said device for generating tones of different pitch, a circuit closer associated with said device, means for selecting said device, means responsive to said selection v for operating the tone generator which is controlled by the position occupied by Said device and for operating said circuit closer, and means in said circuit closer for interrupting `the tone generated by said tone generator to transmit coded audible tone impulses which indicate by the number of coded impulses the device selected and by the pitch of the tone the position of the device.,

2. In a signalling system, a device having a plurality of positions, a tone generator for each position of said device forv generating tones of different pitch, a circuit closer` associated with said device, means Vfor selecting said device, means responsive to said selecftion for operating the tone generator which temeer its rst position, means for operating said circuit breaker to its second position, a control switch, a calling device for transmitting a variable number of impulses in each successive operation thereof, means responsive to the first series of impulses transmitted by the :first operation of said calling device for directively operating said switch to select said device, means for thereafter maintaining said switch in its selecting position during successive series 0I" impulses transmitted by the successive-re-operations of said calling device, and. means in said switch thereafter responsive to alternate series f of impulses transmitted by alternate re-operations of said calling device for operating said first means to operate the device to its first position and responsive to the intermediate alternate series of impulses transmitted by the intermediate alternate re-operations of said calling .device for operating said secondV means to operate the device to its secondposition.

In witness whereof, I hereunto subscribe my name this 30th day of March, A. D. 1928.

MARTIN L. NELSON.

th device, means for operating said device from one position to another position, and means responsive to said operation for stop. ping the said operating tone generator and for operating another of said generators whereby the tone of the code impulses is altered to indicate the altered device.

3. In a signalling system wherein an electromagnetic device having a plurality ofpositions is adapted to be operated from posiposition of said tion to position, means for transmitting an audible code signal of variable tone and predetermined code which simultaneously indicates the said device and its occupied'position, and means responsive to each change in position of said device for altering only the tone of said signal to indicate the new occupied position of said device.A

4; In a remote control system, an electromagnetic devioe having a plurality of positions, a control switch, a calling, device for transmitting a variable number of impulses of uniform duration in each successive operation thereof, means responsive to the rst series of impulses transmitted by the first operation of said calling device for directively operating said switch to select said device, means for thereafter maintaining said switch in its selecting position during successive series of impulses transmitted by the successive re-operations of said calling device, and means in said switch thereafter responsive to the successive series of impulses transmitted by the successive re-operations of said calling device for successively changing said device to alternate positions 5. In a remotecontrol system, a circuit breaker having a first and a second position,

means for operating said circuit breaker to iis 

